sudomod

Hey guys so I saw a few questions on the the forums about cutting power to the speakers when headphones are plugged into the jack. I've managed to find a solution using the original GB jack that is relatively clean so I'm here to share how I did it.

This is the pinout for the original jack, notice the 2 switch pads A and B.



This was how I did the GB jack setup:



You need to desolder Switch B so that it no longer has contact with Ground. Switch B is connected to Switch A, but only when no plug is connected. Red wire is (+) going to the speaker and black wire is (-) going to ground. Blue wire is from USB audio to L+R (I did mono sound to headphone rather than stereo. You can theoretically do stereo but the sound going to speaker will be mono). Blue/white wire is ground from USB audio. The orange wire is a bridge for L+R to Switch B. This means under normal conditions, the signal will go all the way to speakers but when headphone jack is inserted, the connection between Switch B and Switch A is cut, providing only signal to headphones.

EDIT: Ok guys, finally had some free time so I'm adding the wiring schematic I used in full here. This includes a pot that will control both speaker and headphone volume as well as the addition of the Adafruit amp.

ktechelonbreak wrote:Hey guys so I saw a few questions on the the forums about cutting power to the speakers when headphones are plugged into the jack. I've managed to find a solution using the original GB jack that is relatively clean so I'm here to share how I did it.

This is the pinout for the original jack, notice the 2 switch pads A and B.



This was how I did the GB jack setup:



You need to desolder Switch B so that it no longer has contact with Ground. Switch B is connected to Switch A, but only when no plug is connected. Red wire is (+) going to the speaker and black wire is (-) going to ground. Blue wire is from USB audio to L+R (I did mono sound to headphone rather than stereo. You can theoretically do stereo but the sound going to speaker will be mono). Blue/white wire is ground from USB audio. The orange wire is a bridge for L+R to Switch B. This means under normal conditions, the signal will go all the way to speakers but when headphone jack is inserted, the connection between Switch B and Switch A is cut, providing only signal to headphones.

Thanks for this, also any idea how to wire the volume wheel to this setup?

You could have the L+R output from USB to pot L or R, then output that to the headphones. I'd still have the USB ground go straight to the headphone ground. If using an amplifier, I'd put the pot after the mono sound out from the amplifier.

Awesome work. Nice and clear directions. You should get this posted under hardware>guides

Thanks for sharing, this is very useful!

Only thing missing from this is a wiring schematic! I'd like to do this with an amplifier but was confused at that explanation. A visual would be amazing. Thanks for the guide

Kilren wrote:Awesome work. Nice and clear directions. You should get this posted under hardware>guides

Looks like that's been done, thanks mods!

Hei!

I'm lost.

How would you do stereo with this setup? Also, has anyone managed to connect the volume wheel to this?

Should it be

Audio out -> Volume wheel -> the original PCB with a headphone jack and a speaker connected to it? Or something else?

I'm guessing if using and amplifier it would just go between the original PCB (this small one with the heapdhone jack) and the speaker?

Bump, updated to include a schematic.

ktechelonbreak wrote:Bump, updated to include a schematic.

Thanks for the schematic, does your speaker cut out when headphone are plugged in and then back to speaker after headphones are removed?

Im using this amp https://www.sparkfun.com/products/11044

I can get the volume working and either the speaker on its own or the headphones on its own but when i connect them all together i cant get both to work. Im sure ive followed your wiring but the only difference is that the volume wheel has its own pins on the amp and the two output pins as well. any ideas?